Experimental Study On Sesamin Enhancing The Apoptosis Of Lung Cancer Cells Induced By Gemcitabine

Object: Gemcitabine is one of the drugs for the treatment of locally advanced and metastatic lung cancer.Because of its side effects and drug resistance of tumor cells to chemotherapy,the efficacy of gemcitabine in clinical treatment is not satisfactory.Sesamin is a natural product with anticancer effects;however,studies on the anticancer effects of sesamin combined with gemcitabine administration in lung cancer are rare.Here,we investigated the effects of sesamin and gemcitabine on lung cancer(A549,PC9)cell lines and explored the potential mechanisms.Methods: The survival rates of A549 and PC9 cells treated with sesamin and gemcitabine were detected by MTT method,and the half inhibitory concentration(Half-inhibitoryconcentration,IC50)was calculated,and the cells were divided into control group(group C,isovolumetric medium),sesamin group(group S,sesamin 40μg/ml),gemcitabine group(group G,gemcitabine 1 μg/ml)and sesamin combined with gemcitabine group(SG group,sesamin 40 μg/ml+ gemcitabine 1 μg/ml).The cell survival rate was detected by MTT method,the invasive ability of cells was detected by scratch repair test,the cell cycle was detected by flow cytometry,the apoptosis rate was detected by Annexin V-FITC/PI staining,the apoptotic cells were observed by TUNEL staining,the expressions of apoptosis-related proteins Bax,Bcl-2,Caspase-3 and endoplasmic reticulum stress-related apoptotic proteins GRP78,GADD153,IRE1 α,P-IRE1 α,JNK,P-JNK and Caspase-12 were detected by Western Blot.Results: 1.Sesamin(IC50)and gemcitabine(IC50)were used to treat A549 and PC9 cells,respectively.MTT assay showed that the cell survival rate of the combined group was significantly lower than that of the single drug group,and the cell survival rate of the single drug group was lower than that of the blank group.2.The scratch results showed that the scratch repair rate in the combined group was significantly lower than that in the single drug group,and the scratch repair rate in the single drug group was significantly lower than that in the blank group(*P < 0.05,**P <0.01).3.The results of Annexin V-FITC/PI staining showed that the apoptosis rate in the combination group was significantly higher than that in the single drug group,and the apoptosis rate in the single drug group was significantly higher than that in the blank group,and the difference was statistically significant(***P < 0.001,****P <0.0001).4.Under the fluorescence microscope,the apoptotic cells contracted,the cytoplasm shrunk,and the apoptotic bodies of nuclear fragments were observed.In the same visual field,the apoptotic cells in the combined group were significantly higher than those in the single drug group,and the apoptotic cells in the single drug group were significantly higher than those in the blank group,and the difference was statistically significant.(*P < 0.05,**P < 0.01,***P < 0.001,****P < 0.0001).5.In A549 and PC9 cells,compared with the blank group,the Bax/Bcl-2 ratio and Caspase-3 protein expression in the combined group were significantly higher than those in the single drug group,and the protein expression in the single drug group was significantly higher than that in the blank group(*P < 0.05;**P < 0.001;****P <0.0001).6.Flow cytometry showed that the G1 phase arrest of cells in the combination group was significantly higher than that in the single drug group,and that in the single drug group was significantly higher than that in the blank group,and the difference was statistically significant(*P < 0.05,***P < 0.001,****P < 0.0001).7.In A549 and PC9 cells,the protein expressions of GRP78,GADD153,IRE1 α,P-IRE1 α,JNK,P-JNK and Caspase-12 in the combined group were significantly higher than those in the control group,and the difference was statistically significant.(**P < 0.01;***P <0.001;****P < 0.0001).Studies have shown that IRE1 α / JNK signal pathway is involved in sesamin and gemcitabine-induced apoptosis of non-small cell lung cancer cells.Conclusion: 1.Sesamin effectively enhances the anti-proliferation and anti-migration effects of gemcitabine on human lung adenocarcinoma A549 and PC9 cells.2.Sesamin may enhance the cell cycle arrest effect of gemcitabine in G0/G1 phase of human lung adenocarcinoma A549 and PC9 cells.3.The IRE1 α / JNK signal pathway of endoplasmic reticulum stress pathway may be involved in sesamin enhancing the apoptosis of human lung adenocarcinoma A549 and PC9 cells induced by gemcitabine.